In social play children learn to negotiate with others, how to please others, and how to modulate and overcome the anger that can arise from conflicts– Peter Gray (Free to learn)

Kenneth H. Rubin is a Professor of Human Development and Quantitative Methodology and Founding Director, Center for Children, Relationships, and Culture at the University of Maryland. Rubin’s area of research work has been mainly related to child and adolescent social development, peer and parent-child relationships.
Rubin and his co research associates have been working in understanding children’s social, dramatic and cognitive play. The research studies conducted in this area lead them to findings which were very similar to Mildred Parten and Sara Smilansky explanations about play. The studies also lead to successful combining of Parent and Smilansky categories of play.

The results obtained from Rubin’s and his associates studies clarifies of children’s play in accordance to their developmental milestone. By combining Parten’s and Smilansky’s play categories Rubin and his associates proposed the below theory of play outlined in the table below;